The wikipedia page on the Dirac delta function offers the following heuristic definition of the Dirac delta function:
$$\delta(x) = \begin{cases} +\infty, & x = 0 \\ 0, & x \ne 0 \end{cases}$$
whilst acknowledging that the Dirac delta function in fact needs to rigorously defined as either a distribution or a measure. My question is does anyone know of a citation/reference on this in either a textbook or academic journal article?
You can catch a review on "Basic Circuit Theory"
https://www.amazon.com/Basic-Circuit-Theory-Charles-Desoer/dp/0070165750